對話……
off the top of one's head
頭頂脫落了（忘得一乾二淨）

Jerry: Hi Brian. How are things?
Brian: Oh fine. By the way, thanks for your advice.
Jerry: What advice was that?
Brian: Don’t you remember? Alice and I were having problems and you said leave her alone for a couple of days, to think things out.
Jerry: Did I say that?
Brian: Yes. One day last week. Tuesday I think it was.
Jerry: Really?
Brian: Mmm. You must remember! I came to your house and told you all about it, and you said “Leave her alone for a couple of days”.
Jerry: Oh, yes... But actually I think I just said the first thing that came into my head.
Brian: Well it was jolly good advice, even if it was off the top of your head.

傑瑞：嗨，布萊恩。最近過得怎樣？
布萊恩：喔，很好啊，順便謝謝你的建議。
傑瑞：那是什麼建議？
布萊恩：你不記得了嗎？ 愛麗絲和我間有問題，你說讓她靜一靜，想辦法解決。
傑瑞：我這麼說嗎？
布萊恩：是的，上周某一天，應該是周二說的。
傑瑞：真的嗎？
布萊恩：嗯，你一定記得的吧，我到你家，告訴你一切，你說：「這幾天別打擾她」。
傑瑞：噢，是囉......但實際上我想我就是說了想到的第一件事。
布萊恩：嗯，那是一個非常好的建議，即使你已經忘得一乾二淨。